Abstract
The basic objectives of this study were to identify and evaluate changes, if any, in driver performance resulting from altered median visibility on a divided highway. The effects to be ascertained would be those manifested in vehicle speed and vehicle lateral placement “before” and “after” median delineation treatments. Since the purpose of delineating medians is to enable drivers better to follow the path of traffic lanes, it was reasonably hypothesized that the effectiveness of this treatment should be reflected in improved traffic operation characteristics over the delineated section of roadway.